<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .sousuo-da{
            width: 100%;
            height: 44px;
            background-color: red;
            display: flex;
        }
        .an{
            height: 44px;
            width: 44px;
            background-color: red;
        }
        .sousuo{
            width: 100%;
            height: 44px;
            background-color: red;
            display: flex;
        }
        .sousuo sou1{
            width: 100%;
            height: 30px;
            background-color: white;
        }
        .deng{
            align-items: center;
            float: right;
            height: 44px;
            width: 44px;
            background-color: red;
            display: flex;
        }
    </style>
</head>
<body>
    <div class="sousuo-da">
        <div class="an"></div>
        <div class="sousuo">
            <div class="sou1"></div>
        </div>
        <div class="deng">登录</div>
    </div>
    
</body>
</html>